Rail bond terminal pin



Feb. 23, 1943. E, SABOL 2,311,873

RAIL BoNn TERMINAL PIN Filed Feb. 25, 1.942

Fig.`1.

INVENTOR Patented Feb. 23, 1943 RAIL BOND TERMINAL :PIN

Ernest J Sabol,

Richard Wilson,

Pittsburgh, Pa., assignor, by

John Wilkinsburgk, Pa., copartners trading as Hanlon &

Wilson Company Application February .25, 1942,

1 Claim.

This invention relates generally to rail bonds and more particularly to a rail bond terminal pin which when driven into the rail bond terminal expands the stud of the terminal into tightengagement with the rail. The driving pin is of such construction that after having been driven intothe terminal to secure .the stud portion of the terminal to the rail it will remain rmly gripped in the terminal head and will not be loosened by the vibration to which it is subjected.

As is well known, rail bonds are used for connecting the ends of adjacent railway rails in order to form a part of the electric circuit of a signaling system. In the type of rail bond terminal to which the present invention the kind which has an expansible stud adapted to be received in the cavity in the rail. A soft metal,

stud and a pin is inserted into the bore and driven into or against the soft copper, causing it to expand and thereby expand thevstud of the terminal into tight engagement with the rail.

In terminals of the'type herein referred to, considerable difficulty has been encountered in providing a terminal in locked in the terminal as not to become loosened by vibrations caused by the train running on the rail to which ythe bond is connected. The terminal is subjected in use to extreme vibrations which in time tend to cause the pin to become loose from the terminal and the pin lost, making the relates, the terminal is of which the pin is so tightly` bond unfit for reuse without the pin, in case ythe bond is to be removed for any of the following reasons: track moving, building up of track -ends or relocation of old steel to locations where trafc demands are not so great. This practice is not uncommon with many of the railroads. One of the original requisites for an all around rail head bond was that lthe bond be of -such design that it can be removed and reinstalled. Another reason for locking the pin within the terminal head is to reduce to a minimum the possibility of the pins vibrating loose and being lost in transit when shipped.

In accordance with the erally speaking, the body of the pin is provided with one or more projections extending at an angle to the pin axis, the cross sectional area of the pin when taken through the projection being greater than the cross sectional area of the corresponding part of the bore in the terminal head, so that when the pin is driven into the terminal to expand the stud of the terminal into tight engagement with the rail, the projection or projections on the body of the pin bite into the terminal present invention, genshowing one form of boreand is expanded by driving in Serial No. 432,232

head, .thereby securely locking the pin in the head. The projection or projections formed on the body .of the pin may take various forms but in all of them the projections extend at an angle to the pin axis rather than extending parallel to the pin axis, thereby providing better locking of the pin in the terminal head.

In the accompanying drawing, which illustrates several preferred embodiments of my invention:

Fig. l is a horizontal section through a portion of a railway rail and a portion of a railway bond V driving pin for expanding the stud oi the 'terminal into tight engagement with the rail;

Fig. 2 is a Side Fig. l;

Fig. 3 is a combination plane and front elevation of a modiiied form of driving pin; and

Figs. 4 through 7 are front elevations of other forms oi vdriving pins.

Fig. l shows the terminal, which is indicated generally by the reference numeral 2, locked in place in the railway rail 3. The rail bond comprises a conductor d such as a plurality of wires, the end 5 of the conductor being encased in a sleeve E, both of which are made integral with the head l of the terminal by electric welding the conductor end and sleeve end to the terminal head. 'The -terminal comprises the head 'l and an expansible stud 8 which fits into a recess er cavity 9 in the rail. A bore it extends through the head and through a substantial portion of the length o the stud 8, the lower end of the bore being closed by the end'wall l l of the stud. A soft metal, for example copper, or other material capable of flowing under pressure, designated by the reference -niuneral i2, is located in the inner end of the the pin I3. The inner end of the pin l3is provided with a reduced portion lll which in the embodiment shown is of conical shape and acts as an expander for penetrating the copper i2. When the pin is driven into the position shown in Fig. l, it expands the elevation of the pin sho-Wn in l copper and also expands the stud 8 into tight engagement with the rail cavity.

The present invention relates particularly to ythe driving pin I3 and provides a pin which upon being driven into the position shown in Fig. l has portions which bite into the terminal head 1 so as to securely lock the pin in the terminal head. In the embodiment shown in Fig. 2, the pin YI3 has a body portion i5, and an expander section I4 of smaller cross sectional area than the body portion. The body of the pin is provided with a plurality of projections Ilia and Ib, the projections in this embodiment being in the form of annular beads or rings. The cross sectional area of the pin when taken through the leading annular projection I6a is greater than the cross sectional area of the bore I of the terminal head. The cross sectional area of the pin when taken through the following annular projection I 5b is somewhat larger than the cross sectional area of the pin when taken through the leading annular projection I 5a. This construction in which the bead I 6b is of larger area than the bead IIa serves a twofold purpose. First, a better bearing is provided to maintain alignment of the pin axis with the axis of the bore of the terminal head. Second, the bead I6a being slightly larger in cross sectional area than the cross sectional area of the bore of the terminal head, provides a means of locking the pin in frictional engagement. Bead I 6b being larger in cross sectional area than bead IBa, gouges the metal of the terminal head, causing it to flow, thereby decreasing the cross sectional area of the bore of the terminal head in that portion of the bore between the two annular beads I Sa and I6b. This insures a rm locking of the pin by Virtue of the sealing. This will insure a firm locking of the pin by virtue of the frictional engagement of each of the beads Ia and IBb with the terminal and by virtue of sealing the bead I 6a in the terminal, due to the gouging action of the bead ISI).

In the embodiment shown in Fig. 3, the body portion I3 has an annular flange I8 which has a larger cross sectional area than the cross sectional area of the body I3. The flange provides a shoulder I9 between it and the body portion of the pin. It will be noted that the flange tapers toward the end of the pin at which the expander section I4 is located. This tapering of the ange I8 aids in driving the pin into the terminal, while the provision of the shoulder I9 insures that after the pin has been driven into the terminal head and the iiange has bitten into the head, the pin will not become loosened due to vibrations.

The embodiment illustrated in Fig. 4 is similar to that shown in Fig. 3, except that the flange 20, which corresponds to the ilange I8, does not taper but is of the same diameter throughout and therefore provides two shoulders 2I between the iiange and the body of the pin.

In the embodiment shown in Fig. 5, there are a plurality o1" projections 22 each having a larger cross sectional area than the cross sectional area of the body I3 of the pin. Each of the projections 22 is made up of two surfaces 23 and 24, so as to provide V-shaped projections and the V-shaped recesses 25 between the projections. The projections 22 bite into the head in a manner similar to the iianges I8 or 2D or the beads I6 in the embodiments previously described. In the embodiments illustrated in Figs. 2 through 5, it will be noted that the projections which bite into the terminal head are all annular in shape, although differing somewhat in their individual configuration and differing also in the number of projections which are used.

In the embodiments shown in Figs. 6 and 7, the body of the pin has a surface which is made up of a multiplicity of small projections. In Fig. 6, there is a series of grooves 26 extending diagonally downward from left to right and another series of grooves 2'! extending diagonally downward from right to left, these two series of grooves intersecting each other to form the numerous square projections 28 which form in effect a roughened surface on the body of the pin. The cross sectional area of the pin is slightly larger than the cross sectional area of the bore I0, so that these numerous projections 28 bite into the terminal head when the pin is driven into the position shown in Fig. 1.

The embodiment shown in Fig. 7 is quite similar to that shown in Fig. 6. The body of the pin shown in Fig. 7 is provided with helical grooves 29 and straight diagonal grooves 30 which intersect eacli other so as to form the diamond shaped projections 3| The sides of the body portion are made of the rounded portions 32 formed by the intersecting grooves. In this embodiment, in order for the pin to become loosened it would be necessary not only to overcome the frictional engagement due to the diamond shaped projections biting into the terminal head but it would also be necessary to cause the pin to rotate in the head. It will be seen, therefore, that this embodiment provides a pin which will withstand enormous vibrations without becoming loosened from the terminal head.

From the above description, it will be apparent that I have provided a rail bond terminal pin adapted to be driven into a terminal in order to cause the stud of the terminal to be expanded into tight engagement with the rail and likewise have provided a pin which bites into the terminal head and which will, therefore, not become loosened due to vibrations of the terminal. In all of the embodiments described, it is preferred to heat treat the pins in order to harden them, thereby insuring durability when subjected to repeated impact loads with a hammer, spring loaded plunger or press employed to install the rail bond terminals.

While I have illustrated several preferred embodiments of the invention, it is to be understood that the invention is not limited thereto but may be otherwise embodied or practiced within the scope of the following claim:

I claim:

A rail bond terminal pin adapted for use in connection with a terminal having a head, an expansible stud adapted to be received in a rail cavity. a bore extending through the head and through a substantial portion of the length of the stud, one end of the bore being closed by the end wall of the stud. and a relatively soft material in the bore of the stud, said pin having a body portion and an expander section of less cross sectional area than said body portion, said expander section adapted to be driven into said relatively soft material to expand the stud into tight engagement with the rail, the body portion of the pin being provided with at least one annular projection extending at an angle to the pin axis, said annular projection tapering toward the inner end of the pin to aid in driving the pin into the terminal head` the cross sectional area of the pin when taken through said annular projection being greater than the cross sectional area of the bore of the terminal head, so that said projection bites into the terminal head when the pin is driven into the head, whereby the pin is locked in the head.

ERNEST J. SABOL. 

